Picker device of hosiery knitting machine

ABSTRACT

A picker device having an up-picker mechanism (A) and a down-picker mechanism (B) for increasing and decreasing stitches in knitting a heel portion and a toe portion of hosiery. When the knitting of the heel portion or the toe portion is started, a short butt (2a) of a knitting needle in a knitting level comes in contact with a front end portion (17a or 18a) of an up-picker (17 or 18) as a knitting cylinder alternately rotates forward and backward. The up-picker (17 or 18) is thereby rotated horizontally and a rear end portion (17b or 18b) of the up-picker (17 or 18) is guided by an inclined guide slot (20a or 20b), so that the rear end portion (17b or 18b) is lowered and thus thus the front end portion (17a or 18a) of the up-picker (17 or 18) is raised. The knitting needle (2) is thereby raised from above a stitch cam (9a or 9b) to a position above a center cam (8), whereby the knitting needle (2) is moved to a non-knitting level and thus one stitch is decreased. When one stitch is increased, the short butt (2a) of the knitting needle (2) in the non-knitting level presses a front end portion (25a) of a down-picker (25). The down-picker (25) is guided by an inclined cam portion (21a1 or 21a2) and thereby lowered. Thus, the knitting needle is returned to the knitting level. An actuator (29) that is controlled with a signal received from a knitting control unit (35) locks the front end portion (25a) of the down-picker (25) to a predetermined position. Malfunction or the like of the knitting machine caused by rebounding of the pickers (17, 18, and 25) is suppressed by coil springs (19a and 33).

TECHNICAL FIELD

The present invention relates to a picker device of hosiery knittingmachine for knitting a heal portion and a toe portion of hosiery byplain knitting method, a jacquard knitting method, and the like, and inparticular, to a picker device including an up-picker and a down-picker.

BACKGROUND ART

Conventionally, stockings and socks (hosiery) are knitted in the orderof a leg portion, a heel portion, an instep portion, and a toe portion.The heel portion and the toe portion are knitted by increasing anddecreasing stitches along a gore line. The heel portion and the toeportion of hosiery are knitted by a picker device that has an up-pickerand a down-picker. Conventionally, the leg portion and the instepportion are knitted by continuously rotating a knitting cylinder of theknitting machine. On the other hand, when the heel portion and the toeportion are knitted, the knitting cylinder is switched to oscillation oralternate forward and backward rotation. When the heel portion or thetoe portion is knitted, the number of stitches is gradually decreasedand then increased. When the stitches are decreased, a butt of aknitting needle is raised by an up-picker and the knitting needle ismoved to a non-knitting level over a center cam. On the other hand, whenthe stitches are increased, a knitting needle in the non-knitting levelis lowered to a knitting level by a down-picker. Whenever the knittingcylinder of the knitting machine is oscillated or rotates forward andbackward, the up-picker and the down-picker are abutted by butts ofknitting needles at their forward ends, thereby raising and lowering therespective knitting needles. Conventionally, a pair of up-pickers areprovided. These up-pickers are referred to as a left-side up-picker anda right-side up-picker. These up-pickers are connected by a connectingmember so that they move in liaison in vertically different directions.A plate-shaped picker cam is used to raise the up-picker while holding aneedle butt. Likewise, for the down-picker, another picker cam is used.This picker device is disclosed in Japanese Patent Laid-Open PublicationNo. 31-8933.

In the above described device, when the frequency of the oscillatingmotion of the knitting cylinder becomes high as the speed of theknitting machine is increased, there occurs wear of the connecting plateconnecting the left-side up-picker and right-side up-picker and theconnecting pins therebetween. Thus, the knitting operation becomesunstable and thereby the knitting machine malfunctions with resultantlack in reliability. In addition, since the construction of the pickerdevice is complicated, the assembling, adjustment, maintenance andinspection become troublesome.

In the preceding paragraph, problems involved in the conventionalup-picker and down-picker were described with respect to the ordinaryplain knitting and tuck knitting.

On the other hand, when a variety of patterns are knitted, one to fouryarn feeders for knitting motif patterns may be provided along with oneor two ground yarn feeders for knitting jacquard patterns. When fourpattern yarn feeders are provided, a motif pattern with four colors canbe knitted.

For example, in the case of knitting a jacquard pattern wherein thewidth of the pattern is narrow, no problem will occur even if the widthof a knitting needle group in a knitting course is narrower than thewidth of the front end of the down-picker. On the other hand, if thewidth of the knitting needle group in the knitting course (that is thewidth of a region lacking the knitting needles in a non-knitting course)is greater than the width of the front end of the down-picker, the frontedge of the down-picker is raised, in the knitting needle lackingregion, from a low non-operative position to a high position immediatelybelow a leveling cam. Thus, knitting needles that should not participatein the pattern knitting come in contact with the front end of thedown-picker. Consequently, the knitting needles are lowered from thenon-knitting level to the knitting level, thereby disordering thejacquard pattern of the instep portion and making it impossible to knitthe heel portion.

Objects of the present invention are to solve the above describedproblems. A main object of the present invention is to provide a pickerdevice of hosiery knitting machine that can prevent wear of a connectingportion of an up-picker and a down-picker and that can be relativelysimply constructed.

Another object of the present invention is to provide a picker device ofhosiery knitting machine that can correctly knit a jacquard patternwithout defect of a heel portion even if the width of a knitting needlelacking region in a non-knitting course is greater than the width of thefront end of a down-picker.

DISCLOSURE OF THE INVENTION

The present invention is a picker device of a hosiery knitting machinehaving a knitting cylinder, a machine frame provided outside theknitting cylinder, a center cam, a pair of first and second stitch cams,and a leveling cam, the knitting cylinder supporting a number ofknitting needles for upward and downward movement, the knitting needleshaving butts, respectively, the center cam being supported by themachine frame, the first and second stitch cams being disposed on bothsides of the center cam, the leveling cam being supported by the machineframe, the picker device comprising, an up-picker mechanism, and adown-picker mechanism, wherein the up-picker mechanism comprises, afirst up-picker formed in a lever shape and having a first front endportion and a first rear end portion, the first front end portion beingdisposed above the first stitch cam, the first rear end portion beingdisposed on a far side of the knitting cylinder, a first support meansfor supporting the first up-picker at an intermediate portion thereof sothat the first up-picker is rotatable about a vertical axis and ahorizontal axis, a second up-picker formed in a lever shape and having asecond front end portion and a second rear end portion, the second frontend portion being disposed above the second stitch cam, the second rearend portion being disposed on a far side of the knitting cylinder, asecond support means for supporting the second up-picker at anintermediate portion thereof so that the second up-picker is rotatableabout a vertical axis and a horizontal axis, a first inclined guidemeans engaging the rear end portion of the first up-picker for graduallylowering the first rear end so as to move the first front end portion ofthe first up-picker to an upper position above the center cam along witha knitting needle that is caused to abut against the first front endportion, when the butt of the knitting needle in a knitting level of theknitting cylinder rotating in a first direction is caused to move to andabut against the first front end portion of the first up-picker to movethe first front end portion in such a manner that the first up-picker isrotated about the vertical axis, a first elastic means for applying sucha force to the first up-picker to lower the first front end portion, asecond inclined guide means engaging the second rear end portion of thesecond up-picker for gradually lowering the second rear end so as tomove the second front end portion of the second up-picker to an upperposition above the center cam along with a knitting needle that iscaused to abut against the second front end portion, when the butt ofthe knitting needle in a knitting level of the knitting cylinderrotating in a second direction is caused to move to and abut against thesecond front end portion of the second up-picker to move the secondfront end portion in such a manner that the up-picker is rotated aboutthe vertical axis, a second elastic means for applying such a force tothe second up-picker to lower the second front end portion, andinterconnection means for coupling and rotating the first up-picker andthe second up-picker in the same direction about the vertical axis andin opposite directions about the horizontal axis, wherein thedown-picker mechanism comprises, a down-picker having a front endportion and a rear end portion, the front end portion being disposedimmediately below the leveling cam, the rear end portion being disposedon a far side of the knitting cylinder, the down-picker being supportedat the rear end portion thereof for upward and downward rotation by ahorizontal shaft, means for supporting the rear end portion of thedown-picker so that the down-picker is rotatable horizontally from aneutral position, a cam guide means for moving the down-picker downwardwhen the down-picker is rotated horizontally from the neutral position,a locking means for locking rotating position of the horizontal shaft sothat the down-picker is selectively placed at a first rotating positionor a second rotating position of the horizontal shaft, the front endportion of the down-picker being at the first rotating position adaptedfor contact with the butt of the knitting needle in the non-knittinglevel, the front end portion of the down-picker at the second rotatingposition being free from contact with the butt of the knitting needle inthe non-knitting level, and an elastic means for urging the down-pickertoward the leveling cam.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side sectional view showing part of a picker device ofhosiery knitting machine according to the present invention;

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a perspective view showing an up-picker mechanism of FIGS. 1and 2;

FIG. 4 is a perspective view showing a down-picker mechanism of FIGS. 1and 2;

FIG. 5 is a partial sectional side view showing the down-pickermechanism;

FIG. 6 is a partial sectional side view showing the down-pickermechanism in a different state;

FIG. 7 is a development diagram showing positions of cams and yarnfeeders;

FIG. 8 is a plan view showing butts of knitting needles;

FIG. 9 is a plan view showing the butts of knitting needles in adifferent state;

FIG. 10 is a schematic diagram for explaining various portions ofhosiery;

FIG. 11 is a schematic diagram for explaining the relation among acenter cam, stitch cams, and up-pickers;

FIG. 12 is a schematic diagram for explaining the relation between aleveling cam and a down-picker;

FIG. 13 is a development diagram showing the relation among variouscams, needle butts, and down-picker of the hosiery knitting machine;

FIG. 14 is a plan view according to a modification of the embodiment ofFIG. 13;

FIG. 15 is a development diagram similar to FIG. 13 but showing adifferent working condition from FIG. 13;

FIG. 16 is a plan view of FIG. 15;

FIG. 17 is a development diagram similar to FIG. 13 but showing adifferent working condition from FIG. 13; and

FIG. 18 is a plan view of FIG. 17.

BEST MODES FOR CARRYING OUT THE INVENTION

Next, with reference to the accompanying drawings, embodiments of thepresent invention will be described.

Up-picker mechanism

In FIG. 1, reference numeral 1 designates a knitting cylinder of ahosiery knitting machine. As is known in the art, the knitting cylinder1 is rotated either in one direction continuously or in two directions(forward and backward) about a vertical axis thereof. A large number ofvertical needle grooves are formed on the outer peripheral surface ofthe knitting cylinder 1. Knitting needles 2 are inserted into the needlegrooves, respectively. The knitting needles 2 are movable upward anddownward. There are two types of knitting needles 2, one of which has ashort butt 2a, the other of which has a long butt 2b (see FIG. 8). Theknitting needles 2 with the butt 2a are used for knitting a heel portionand a toe portion of hosiery as will be descried later.

A sinker bed 3 is disposed at an upper portion of the knittingcylinder 1. The sinker bed 3 has known sinkers 4. The sinkers 4 areslidable in radial directions of the knitting cylinder 1 by sinker cams6 disposed on a sinker cap 5. The sinker cams 6 operate the sinkers 4 insynchronization with the upward and downward motions of the knittingneedles 2, thereby knitting the hosiery.

As shown in FIGS. 3 and 7, a center cam 8, a right-side stitch cam 9a,and a left-side stitch cam 9b are supported by a machine frame 7disposed outside the knitting cylinder 1. A pair of brackets 10 aredisposed in the vicinity of the left-side and right-side stitch cams 9aand 9b and on the machine frame 7. As shown in FIG. 2, the brackets 10are pivoted by vertical shafts 11. As shown in FIG. 3, enlarged trunkportion 12 are integrally formed in the middle of the vertical shafts11. Bell-crank-shaped swing levers 13 and 14 are pivoted at upperportions of the vertical shafts 11. Bent pieces 13a1 and 14a1 are formedon arm levers 13a and 14a of the swing levers 13 and 14, respectively. Acenter portion of a swingable interconnection lever 16 is disposed on amachine table 7a (also see FIGS. 1 and 2) that is incorporated into themachine frame 7. The center portion of the interconnection lever 16 ispivoted by a vertical support shaft 15. Free end portions 16a and 16b(see FIG. 2) of the interconnection lever 16 are in contact with thebent pieces 13a1 and 14a1, respectively so that the interconnectionlever 16 moves in association with the arm levers 13a and 14a. As shownin FIG. 3, through slots 12a are formed in the middle of the trunkportions 12. The slots 12a extend along the trunk portion 12. A first(right-side) up-picker 17 and a second (left-side) up-picker 18 arepassed through, and pivoted within the right-side and left-side slots12a of the trunk portion 12, respectively. The first up-picker 17 andthe second up-picker 18 are swingable upward and downward along theslots 12a.

Picker front end portions 17a and 18a are formed on the up-pickers 17and 18, respectively, at their ends adjacent to the knitting cylinder 1.Known recess portions that are adapted to be abutted by, and support thebutts 2a are formed on mutually remote sides of the front end portions17a and 18a. As shown in FIGS. 2 and 3, the front end portions 17a and18a are disposed in the vicinity and above the first stitch cam 9a andthe second stitch cam 9b, respectively. Thus, the end portions 17a and18a can be lowered into recesses 9a1 and 9b1 in the upper centerportions of the stitch cams 9a and 9b, respectively. The up-pickers 17and 18 have rear end portions 17b and 18b, respectively. The rear endportions 17b and 18b are disposed on the far side relative the knittingcylinder 1. The swing levers 13 and 14 have arm portions 13b and 14b ,respectively. The rear end portions 17b and 18b and the arm portions 13band 14b of the swing levers 13 and 14 are connected by tension coilsprings 19a, respectively. The rear end portions 17b and 18b of theup-pickers 17 and 18 are upwardly pulled by the tension coil springs19a. Thus, as viewed in FIG. 3, the up-pickers 17 and 18 are alwaysurged upward so that they are urged to rotate clockwise. Consequently,the picker end portions 17a and 18a are urged so as to engage in therecesses 9a1 and 9b1 at the upper edge portions of the right-side stitchcam 9a and the left-side stitch cam 9b, respectively. In addition, platemembers are fixedly provided that have inclined guide slots 20a and 20binto which the rear end portions 17b and 18b are slidably fitted,respectively. As shown in FIG. 3, the inclined guide slots 20a and 20bare disposed so that their heights increase as they extend toward eachother.

Thus, for example, in FIG. 3, when the butt 2a of a knitting needle 2pushes the picker end portion 17a leftward, the up-picker 17 is rotatedabout the vertical shaft 11 clockwise, whereby the rear end portion 17bis guided downward by the inclined guide slot 20a. Thus, the picker edgeportion 17a is raised so that it is placed above the center cam 8.

The above-described mechanism constitutes an up-picker mechanism A.

In the development diagram shown in FIG. 7, F1 and F2 represent yarnfeeders used for knitting jacquard patterns. In addition to the yarnfeeders F1 and F2, four yarn feeders F3, F4, F5, and F6 used forknitting motif patterns are provided.

Down-picker Mechanism

As shown in FIGS. 1 and 2, a down-picker mechanism B is provided at adiametrically opposite position relative to the up-picker mechanism Awith respect to the knitting cylinder 1. Next, the down-picker mechanismB will be described.

A leveling cam 21 is provided so as to be opposed to the center cam 8with the knitting cylinder therebetween in the diametric directionthereof. The leveling cam 21 is also shown in FIG. 7. As shown in FIG.1, the leveling cam 21 is secured to a support member 22 on the machineframe 7 along with a pair of cam guide members 21a. A left-side inclinedcam 21a1 and a right-side inclined cam 21a2 are provided on the loweredges of the cam guide members 21a, as shown in FIGS. 4 and 6, ahorizontal shaft 23 is mounted horizontally on the support member 22. Astop shaft 24 is vertically implanted in the middle of the horizontalshaft 23. A small diameter portion 24a and a large diameter portion 24bare formed in an upper portion of the stop shaft 24. A slot 23a isdefined in the middle of the horizontal shaft 23 in the axial directionthereof. A base portion of a rod-shaped down-picker 25 is pivoted by thestop shaft 24 in the slot 23a so as to be horizontally rotatable in theslot 23a. A pair of urging levers 26a and 26b are disposed below thehorizontal shaft 23 and pivoted by pins 37a and 37b, respectively, sothat the down-picker 25 can be returned to a neutral position by elasticforce of a tension spring 27 disposed between the urging levers 26a and26b. In FIG. 4, the pin 37b is not seen. Thus, a front end 25a of thedown-picker 25 is normally placed at the neutral position and extends ina concavity formed in the lower portion of the leveling cam 21.

A pair of upper and lower mounting brackets 28b and 28a are secured tothe rear of the support member 22. An actuator 29 such as anelectromagnet is supported by the mounting bracket 28a. As shown in FIG.6, an attraction piece 29a is disposed above the actuator 29. Theattraction piece 29a is pivoted by a support 30. Thus, the attractionpiece 29a can move upward and downward. A working piece 31 is formedintegrally with the attraction piece 29a. A free end portion 31a extendsfrom the working piece 31 so that the free end portion 31a canalternately come in contact with the small diameter portion 24a and thelarge diameter portion 24b. An adjusting screw 32 is threadedly passedin an end portion of the mounting bracket 28b so that the adjustingscrew 32 can adjustably restrict the floating position of the attractionpiece 29a. The mounting bracket 28b and the stop shaft 24 are connectedby way of a tension coil spring 33. A knitting control unit 35 isconnected to the actuator 29 by way of cables 36. The knitting controlunit 35 stores a knitting program.

Operation

The operation of the above-described picker device will be described.

As shown in FIG. 10, ordinarily hosiery is knitted in the order of a legportion 50, a heel portion 51, an instep portion 52, and a toe portion53. When the heel portion 51 and the toe portion 53 are knitted,stitches are increased and decreased along gore lines 54a and 54b. Whenthe leg portion 50 and the instep portion 52 are knitted, the knittingcylinder 1 is continuously rotated only in the forward direction. On theother hand, when the heel portion 51 and the toe portion 53 are knitted,the knitting cylinder is rotated alternately in forward and backwarddirections or oscillated as is known in the art.

Operation of up-picker mechanism

When the heel portion and the toe portion are knitted, knitting needleswith the butt 2a are used. As shown in FIG. 3, when the knittingcylinder 1 rotates forward and backward in oscillation, the butt 2a of aknitting needle 2 moves the front end portion 17a of the right-sideup-picker 17 leftward against the force of the coil spring 19a. At thistime, the butt 2a is caused to engage into the recess portion on theright of the front end portion 17a. As viewed in FIG. 3, the up-picker17 is thereby rotated about the vertical shaft 11 clockwise. Thus, therear end portion 17b of the up-picker 17 is lowered along the inclinedguide slot 20a. Consequently, the front end portion 17a is raised andmoved to a position above the center cam 8. Meanwhile, the swing lever13 rotates about the vertical shaft 11 clockwise through the coil spring19a.

FIG. 11 shows the operation of the above-described up-picker 17. Asshown in this figure, the up-picker 17 is initially placed in a recess9al of the right-side stitch cam 9a. The up-picker 17 is abutted by thebutt 2a and raises the butt 2a to a non-knitting level above the centercam 8. Thus, the knitting needle 2 with the butt 2a does not form astitch. In other words, one stitch is decreased.

When the swing lever 13 rotates clockwise, the arm lever 13a rotates theinterconnection lever 16 in an arrow direction shown in FIG. 3(counterclockwise). Thus, the left-side swing lever 14 is caused torotate clockwise. This rotation is transmitted to the left-sideup-picker 18 through the coil spring 19a. Thus, the rear end portion 18bis pushed toward a higher portion of the inclined guide slot 20b.Consequently, the up-picker 18 rotates about the vertical shaft 11clockwise. The front end portion 18a is thereby lowered and enters intothe recess 9bl of the left-side stitch cam 9b.

In FIG. 3, the above-described operation applies equally to theoperation of the up-picker 18. In other words, when the butt 2a of aknitting needle 2 moves rightward, it comes in contact with the frontend portion 18a of the up-picker 18. The operation of the up-picker 18is shown in the left half of FIG. 11.

The alternate rotations (oscillation) in forward and backward directionsof the knitting cylinder 1 cause the up-pickers 17 and 18 to alternatelyrise and lower. In other words, as shown in FIGS. 8 and 9, theup-pickers 17 and 18 alternately place the needles with the butts 2aabove the center cam 8, thereby decreasing the knitting range of theneedles 2 from a range L1 to a range L2.

As described above, the up-pickers 17 and 18 are constantly urged by thecoil springs 19a in such a manner that the front end portions 17a and18a thereof are moved downward. The rear end portions 17b and 18b of theup-pickers 17 and 18 are moved constrainedly along the inclined guideslots 20a and 20b, respectively. Thus, the hosiery knitting machine isstably operated even at high speed. The engaging portions between theswing levers 13 and 14 and the interconnection lever 16 undergo wear toa lesser degree than conventional link mechanisms using connection pins.

After stitches are decreased from the state of FIG. 8 and to that ofFIG. 9, stitches must be increased by the above-described down-pickermechanism B.

Operation of down-picker mechanism

When the heel portion and the toe portion are knitted, the knittingcylinder 1 is oscillated or rotated alternately forward and backward.For this purpose, the butt 2a of a knitting needle 2 placed at thenon-knitting level is lowered from within the bottom concavity of theleveling cam 21 by means of the down-picker 25 so as to increase thestitches. In other words, in the condition shown in FIG. 6, when theactuator 29 is energized with a signal received from the knittingcontrol unit 35 storing a knitting program, the actuator 29 attracts theattraction piece 29a as shown in FIG. 5. Thus, the working piece 31integral with the attraction piece 29a is rotated against the elasticforce of the coil spring 34 about the support 30. Consequently, theworking piece 31 is disengaged from the large diameter portion 24b ofthe stop shaft 24. The stop shaft 24 is thereby rotated counterclockwiseby the elastic force of the coil spring 33 about the horizontal shaft23. The free end portion 31a of the working piece 31 thus comes incontact with the small diameter portion 24a of the stop shaft 24, whilethe down-picker 25 is rotated to a horizontal position. When theknitting cylinder 1 rotates forward, the butts 2a of two knittingneedles 2 come in contact with the down-picker 25, thereby pushing itleftward (as viewed in FIG. 4). Thus, the down-picker 25 comes incontact with the inclined cam portion 21al that lowers toward the leftof the cam guide member 21a. Consequently, the down-picker 25 is movedin a leftward and downward direction against the elastic force of thecoil spring 33. Since the down-picker 25 and the horizontal shaft 23rotate together, the stop shaft 24 integral with the horizontal shaft 23is also rotated in the same direction as shown in FIG. 6. Thus, the nextbutt 2a does not come in contact with the down-picker 25, but passesbeyond it.

After the arrangement of the long butts 2b (see FIGS. 8 and 9) of theknitting needles 2 have passed, the actuator 29 is deenergized with asignal received from the knitting control unit 35. Thus, the workingpiece 29a is released from the attraction. At this time, since the freeend portion 31a of the working piece 31 is engaged with the largediameter portion 24b as shown in FIG. 6, the down-picker 25 is inclinedin a rightward and downward direction. However, the urging levers 26aand 26b elastically rotate the down-picker 25 in the horizontaldirection, thereby returning the down-picker 25 to the neutral positionbelow the leveling cam 21 (see FIG. 7).

As described above, when the butts 2a come in contact with thedown-picker 25, the down-picker 25 is lowered. This operation is shownin the left half of FIG. 12. Recessed portions are likewise formed atboth the sides of the down-picker 25 as in the case of the up-picker 17.As 10 shown in FIG. 12, two butts 2a are caused to engage the recessedportions. Thus, two knitting needles 2 are returned concurrently fromthe non-knitting level to the knitting level.

The operation in the case when the knitting cylinder 1 rotates backwardis the same as the operation in the case when the knitting cylinder 1rotates forward. In FIG. 4, the down-picker 25 is moved rightward by thebutts 2a. The down-picker 25 is guided by the right-side cam portion21a2 of the cam guide member 21a and lowered. The operation of thedown-picker 25 is shown in the right half of FIG. 12. Thus, two knittingneedles 2 are lowered to the knitting level at a time. In this case, thecoil spring 27 returns the down-picker 25 to the neutral position belowthe leveling cam 21, where the down-picker 25 waits for the nextoperation.

Since the long butts 2 do not participate in knitting the heel portionand the toe portion, they are moved to a float course FC at the low endlevel of the stitch cams 9a and 9b (see FIG. 7). While the butts 2a arein a knitting course KC, the knitting cylinder 1 alternately rotatesforward and backward so as to knit the heal portion and the toe portion.As in the case of the operation of the up-pickers, the butts 2a of theknitting needles 2 raised above the center cam 8 in the non-knittinglevel is lowered by the down-picker 25 placed in the bottom concavity ofthe leveling cam 21, thereby increasing stitches. In other words, as theknitting cylinder 1 alternately rotates forward and backward, two butts2a on the center cam 8 at the non-knitting level are lowered to theknitting course KC at a time.

According to the present invention, after the down-picker 25 has loweredfirst two butts 2a to the knitting course KC, the remaining butts 2a andthereafter the butts 2b pass through the upper surface of the front end25a of the down-picker 25. During this operation, it is necessary toprevent the down-picker 25 from rising and returning into the bottomconcavity of the leveling cam 21. Otherwise, butts 2a that should not belowered would be lowered. To prevent this problem, while the butts 2bare passing through the position of the down-picker 25 and after thebutts 2a are lowered by the down-picker 25, the actuator 29 is switchedfrom the energized state to the deenergized state by a signal from theknitting control unit 35. Thus, the free end portion 31a of the workingpiece 31 is engaged with the large diameter portion 24b of the stopshaft 24. As shown in FIG. 6, the front end 25a of the down-picker 25 isthus kept in a non-working position where the front end 25a does notcome in contact with the butts 2a.

To return the down-picker 25 to the initial working position (shown inFIG. 5), the actuator 29 is energized by a signal received from theknitting control unit 35 so as to attract the attraction piece 29aagainst the force of the coil spring 34. Thus, the free end 31a of theworking piece 31 moves from the large diameter portion 24b of the stopshaft 24 to the small diameter portion 24a thereof. The horizontal shaft23 and the down-picker 25 are returned to positions as shown in FIG. 5for the next down-picker operation.

By oscillating the knitting cylinder 1 forward and backward, thedown-picker 25 is lowered from within the bottom concavity of theleveling cam 21. Thus, two butts 2a are lowered at a time. The knittingrange L2 of the needles 2 with the butts 2a shown in FIG. 9 is thusincreased to the knitting range L1 shown in FIG. 8 so as to knit theheel portion and the toe portion.

According to the present invention, even if a region lacking the buttsof a width T (FIG. 7) that is larger than the width t of the front endof the down-picker 25 passes through a non-knitting level NKC (FIG. 7),jacquard patterns can be reliably knitted with a pattern generatingprogram.

When the leg portion and the instep portion of hosiery are knitted tohave a jacquard patterns with two colors, a first color yarn and asecond color yarn are supplied from different feeders. As shown in FIG.7, while the second color yarn is being knitted, knitting needles 2blthat knit the first color yarn are in the non-knitting course NKC. Onthe other hand, while the first color yarn is being knitted, knittingneedles 262 that knit the second color yarn are in the float course FC.These knitting needles take the knitting course KC (see FIG. 7) duringknitting. As is known in the art, whether the knitting needles with thebutts 2b take the non-knitting course NKC or the float course FC isdetermined by a needle selection device. The knitting needle width T inthe float course FC (namely, the width of the region lacking the buttsin the non-knitting course) depends on how many knitting needles takethe non-knitting course NKC. When the knitting operation shifts from theleg portion to the heel portion, needles (for knitting the instepportion) with the butts 2b that are disposed in half the circumferenceof the knitting cylinder take the float course FC. Needles with thebutts 2a that are disposed on the remaining half circumference knit theheel portion. During this operation, as described above, the needleswith the butts 2a are successively raised to the non-knitting level fromthe opposite sides so as to decrease the number of stitches. Next, theneedles are successively lowered to the knitting level so as to increasethe number of stitches.

Assume that such a wide jacquard pattern is knitted by using theconventional picker device and that the width T of the butts of theknitting needles in the float course FC is larger than the width t ofthe front end 25a of the down-picker 25. In such a case, when the buttsof the knitting needles that are in the non-knitting course NKCfrictionally pass over the upper surface of the down-picker 25, thedown-picker that is to be placed in the lowered non-operative positionis raised to the operative position immediately below the leveling cam21 toward the region lacking the butts of the width T that is largerthan the width t of the down-picker 25. Thus, the down-picker 25 acts onand lowers some of the knitting needles in the non-knitting course NKC.Consequently, the heel portion cannot be correctly knitted, and disorderof the pattern to be knitted occurs.

However, according to the down-picker mechanism of the presentinvention, the actuator 29 securely holds the down-picker 25 at thenon-operative position, so that some of the knitting needles in thenon-knitting course KC are not lowered by the down-picker 25, to theknitting course KC, whereby disorder of the pattern does not occur.

Modification of Embodiment

In the case of the above-described down-picker mechanism, thedown-picker 25 moved under the force of the coil springs 33 and 27.Thus, even if the knitting machine operates at high speed, thedown-picker 25 operates stably without jumping due to rebounding.

As described above, before the heel portion and toe portion of hosieryare knitted, the knitting cylinder continuously rotates forward. Onlywhen the heel portion and toe portion are knitted, the knitting cylinderalternately rotates forward and backward so as to decrease and increasethe stitches. When the stitches are increased, two butts are lowered ata time to the knitting level by the down-picker. After the two butts arethus lowered to the knitting level, the down-picker cannot be returnedto the initial position in the concavity of the leveling cam unless allthe butts have passed the down-picker. Unless the down-picker is presentin the start position in the concavity of the leveling cam, thedown-picker cannot be abutted at its end portion by the butts of theneedles that come in the next backward rotation of the knittingcylinder, and therefore the down-picker cannot be lowered to move theneedles to the knitting level. Thus, until all the butts pass thedown-picker, the down-picker should wait at the lowered position. Toreduce the waiting time, the speed of alternate forward and backwardrotations or oscillation of the knitting cylinder must be increased.

In the hosiery knitting machine, the knitting cylinder respectivelymakes alternate forward and backward rotation with a basic angularvelocity of approximately 1 turn (360°) to knit the heel portion and toeportion of hosiery. Thus, if the knitting cylinder rotates at highspeed, inertia force due to angular acceleration will become large. Inaddition, the knitting operation of the heel portion and toe portioncannot follow the high speed of the knitting machine. Thus, knittingneedles may be broken and/or the cam mechanism will undergo wear.Moreover, the tension applied to the yarn will become too large.Furthermore, constructional elements of the machine will wear,accompanied by frictional heat, whereby the knitting operation willbecome unstable and the quality of the knitted products willdeteriorate.

A modification of the embodiment that can solve such a problem will bedescribed below.

As shown in FIG. 2, according to the embodiment of the present inventiondescribed before, the up-picker mechanism A is placed in opposition tothe down-picker mechanism B with the knitting cylinder 1 therebetween inthe diametrical direction thereof. In contrast, according to themodification of the embodiment, as shown in FIG. 14, two down-pickermechanisms B, B are disposed at positions angularly spaced apart from anup-picker mechanism A by approximately 90°. One of the down-pickermechanisms B, B has a leveling cam 21a and a down-picker 25a. The otherdown-picker mechanism B has a leveling cam 21b and a down-picker 25b. Asshown in FIG. 14, a yarn feeder 60, a needle-raising switch cam 61a, anda needle lowing switch cam 61b are disposed around the knittingcylinder 1. Reference numeral 65 represents a reference position(corresponding to the center position of the heel portion of hosiery).

FIG. 13 is a development diagram of various cams. In this figure, aright-side stitch cam 9a and a left-side stitch cam 9b are disposed onthe right and left of the center cam 8, respectively. The right-sidestitch cam 9a and the left-side stitch cam 9b have upwardly openrecesses in which a known right-side up-picker 17a and a known left-sideup-picker 18a can be placed, respectively. A right-side cushion cam 68aand a left-side cushion cam 68b are disposed below the right-side stitchcam 9a and the left-side stitch cam 9b, respectively. A right-side cam69a and a left-side cam 69b are disposed in the vicinity of theright-side cushion cam 68a and the left-side cushion cam 68b,respectively. A right-side leveling cam 21a and a left-side leveling cam21b are disposed apart from the center cam 8 by approximately 90°(approximately 1/4 of the circumference). The right-side leveling cam21a and the left-side leveling cam 21b have lower concavity in which theright-side down-picker 25a and the left-side down-picker 25b can beplaced, respectively. The raising switch cam 61a and the lowering switchcam 61b are disposed apart from the leveling cams 21a and 21b byapproximately 90° (approximately, 1/4 circumference), respectively. Theswitch cams 61a and 61b are movable in radial directions of the knittingcylinder 1. After the heel portion (toe portion) has been knitted, theneedle lowering switch cam 61b lowers the needles with the long butt 2ato the knitting level 63. The yarn feeder 60 is disposed above thecenter cam 8.

Next, the operation of the modification of the embodiment will bedescribed.

Knitting operation for decreasing stitches by up-pickers

The knitting operation for decreasing the stitches by the up-pickers isperformed in the following manner.

In FIGS. 13 and 14, before the heel portion (toe portion) is knitted,the knitting cylinder 1 rotates forward (namely, counterclockwise). Inother words, needles with short butt 2a and needles with long butt 2bpass through the right-side cam 69a and are then cleared by theright-side stitch cam 9a. The needles with short butt 2a and needleswith long butt 2b make knitting operation, using a yarn supplied fromthe yarn feeder 60, from the center cam 8 to the left-side stitch cam9b. Thereafter, the needles are returned to the tack line by theleft-side cam 69b. By repeating these steps, the knitting operation isperformed. During the operation, the raising switch cam 61a and thelowering switch cam 61b are retracted to the non-operative position.

When the heel portion (toe portion) is knitted, the needle raisingswitch cam 61a is moved toward the axis of the knitting cylinder 1. Whenthe heel porion (toe portion) is knitted, the needle raising switch cam61a raises only the needles with the long butt 2b from the knitting line63 to the non-knitting line 62.

Thus, the needles with the short butt 2a that are disposed on half thecircumference of the knitting line 63 operate to knit the heel portion(toe portion). During this operation, the right-side down-picker 25a andthe left-side down-picker 25b are lowered from the concavities of theright-side leveling cam 21a and the left-side leveling cam 21b to theirnon-operative positions so as not to interfere with the needles with thelong butt 2b in the non-knitting line 62.

Next, the knitting cylinder 1 alternately rotates forward and backwarduntil the heel portion (toe portion) has been knitted. When the knittingcylinder 1 rotates backward or reversely, a first needle with the shortbutt 2b in the knitting line 63 is moved to the non-knitting line 62 bythe left-side up-picker 18a.

When the knitting cylinder 1 rotates forward, a first needle with theshort butt 2a in the knitting line 63 is moved to the non-knitting line62 by the right-side up-picker 17a.

When the knitting cylinder 1 thus repeats the alternate (forward andbackward) rotations, the right-side up-picker 17a and the left-sideup-picker 18b alternately move right end and left end needles with theshort butt 2a in the knitting line 63 to the non-knitting line 62 (theline of the needles with the long butt 2b). Thus, stitches are graduallydecreased so that a predetermined knitting width can be obtained.

Consequently, an arrangement of needles with the long butt 2b is formedin the non-knitting line 62, while on both sides of this arrangement,arrangements of a predetermined number of needles with the short butt 2aare formed.

Stitches are thus decreased by the right-side up-picker 17a and theleft-side up-picker 17b.

Knitting operation for increasing stitches by down-pickers

As shown in FIGS. 13 and 14, when the knitting cylinder 1 rotatesbackward (clockwise), first two needles of the needles with the shortbutt 2a moved to the non-knitting line 62 are lowered at a time to theknitting line 63 by each of the right-side down-picker 25a and theleft-side down-picker 25b. As described above, since the right-sidedown-picker 25a is disposed with a phase difference of approximately 1/4of the circumference to the right, the angular acceleration of theknitting cylinder 1 in the leftward direction can be decreased to theacceleration corresponding to approximately 1/4 of the circumference ofthe knitting cylinder. Similarly, since the left-side down-picker 25b isdisposed with a phase difference of approximately 1/4 of thecircumference to the left, the angular acceleration to the right of theknitting cylinder 1 can be decreased to the acceleration correspondingto approximately 1/4 of the circumference of the knitting cylinder (seeFIGS. 17 and 18).

INDUSTRIAL APPLICABILITY

The present invention can be used for gradually increasing anddecreasing stitches of hosiery including socks and stockings.

We claim:
 1. A picker device of a hosiery knitting machine having aknitting cylinder, a machine frame provided outside the knittingcylinder, a center cam, a pair of first and second stitch cams, and aleveling cam, the knitting cylinder supporting a number of knittingneedles for upward and downward movement, the knitting needles havingbutts, respectively, the center cam being supported by the machineframe, the first and second stitch cams being disposed on both sides ofthe center cam, the leveling cam being supported by the machine frame,said picker device comprising:an up-picker mechanism; and a down-pickermechanism, wherein said up-picker mechanism comprises: a first up-pickerformed in a lever shape and having a first front end portion and a firstrear end portion, the first front end portion being disposed above thefirst stitch cam, the first rear end portion being disposed at a farside of the knitting cylinder; first support means for supporting saidfirst up-picker at an intermediate portion thereof so that said firstup-picker is rotatable about a vertical axis and a horizontal axis; asecond up-picker formed in a lever shape and having a second front endportion and a second rear end portion, the second front end portionbeing disposed above the second stitch cam, the second rear end portionbeing disposed at a far side of the knitting cylinder; second supportmeans for supporting said second up-picker at an intermediate portionthereof so that said second up-picker is rotatable about a vertical axisand a horizontal axis; first inclined guide means engaging the firstrear end portion of said first up-picker for gradually lowering saidfirst rear end so as to move the first front end portion of said firstup-picker to an upper position above the center cam along with aknitting needle that is caused to abut against the first front endportion, when the butt of the knitting needle in a knitting level of theknitting cylinder rotating in a first direction is caused to move to andabut against the first front end portion of said first up-picker to movethe first front end portion in such a manner that said first up-pickeris rotated about the vertical axis; first elastic means for applyingsuch a force to said first up-picker to lower the first front endportion; second inclined guide means engaging the second rear endportion of said second up-picker for gradually lowering said second rearend so as to move the second front end portion of said second up-pickerto an upper position above the center cam along with a knitting needlethat is caused to abut against the second front end portion, when thebutt of the knitting needle in a knitting level of the knitting cylinderrotating in a second direction is caused to move to and abut against thesecond front end portion of said second up-picker to move the secondfront end portion in such a manner that said second up-picker is rotatedabout the vertical axis; second elastic means for applying such a forceto said second up-picker to lower the second front end portion; andinterconnection means for coupling and rotating said first up-picker andsaid second up-picker in the same direction about the vertical axis andin opposite directions about the horizontal axis; wherein saiddown-picker mechanism comprises: a down-picker having a front endportion and a rear end portion, the front end portion being disposedimmediately below the leveling cam, the rear end portion being disposedon a far side of said knitting cylinder, the down-picker being supportedat the rear end portion thereof for upward and downward rotation by ahorizontal shaft; means for supporting the rear end portion of saiddown-picker so that the down-picker is rotatable horizontally from aneutral position thereof; cam guide means for moving said down-pickerdownward when the down-picker is rotated horizontally from the neutralposition; locking means for locking rotating position of said horizontalshaft so that said down-picker is selectively placed at a first rotatingposition or a second rotating position of the horizontal shaft, thefront end portion of said down-picker at the first rotating positionbeing adapted for contact with the butt of the knitting needle in thenon-knitting level, the front end portion of said down-picker at thesecond rotating position being free from contact with the butt of theknitting needle in the non-knitting level; and elastic means for urgingsaid down-picker toward the leveling cam.
 2. The picker device as setforth in claim 1,wherein each of said first support means and saidsecond support means comprises: a vertical shaft rotatably supported bythe machine frame; a trunk portion of the vertical shaft; slot meansformed in said trunk portion and extending along the trunk portion; anda horizontal pin disposed in said slot means for pivoting said firstup-picker or said second up-picker.
 3. The picker device as set forth inclaim 1,wherein each of said first inclined guide means and said secondinclined guide means comprises a member secured to the machine frame andhaving an inclined guide slot.
 4. The picker device as set forth inclaim 1,wherein said up-picker mechanism further comprises: a firstswing lever with a base pivoted about the vertical axis of said firstup-picker, and wherein said first elastic means is a tension spring forconnecting the rear end portion of said first up-picker and said firstswing lever.
 5. The picker device as set forth in claim 4,wherein saidup-picker mechanism further comprises: a second swing lever with a basepivoted about the vertical axis of said second up-picker, and whereinsaid second elastic means is a tension spring for connecting the rearend portion of said second up-picker and said second swing lever.
 6. Thepicker device as set forth in claim 1,wherein said interconnection meansis a swingable lever with a center portion pivoted by a vertical shaftdisposed between said first swing lever and said second swing lever, theinterconnection lever having two end portions engaging said first swinglever and said second swing lever.
 7. The picker device as set forth inclaim 1,wherein the rear end portion of said down-picker is supported inthe horizontal shaft so that the front end portion thereof is rotatablehorizontally.
 8. The picker device as set forth in claim 1,wherein saidcam guide means and the leveling cam are disposed on the same side withrespect to the circumference of the knitting cylinder.
 9. The pickerdevice as set forth in claim 1,wherein said locking means comprises:knitting control means; an actuator having an operative state and anon-operative state depending upon a signal received from said knittingcontrol means; and working means disposed between said actuator and thehorizontal shaft for causing the horizontal shaft to rotate to the firstrotating position when said actuator is in the operative state and forcausing the horizontal shaft to rotate to the second rotating positionwhen said actuator is in the non-operative state.
 10. The picker deviceas set forth in claim 9,wherein said working means comprises: a stopshaft disposed perpendicular to the horizontal shaft and having a largediameter portion and a small diameter portion; and a lever-shapedworking piece rotatable depending upon the operative state or thenon-operative state of said actuator and selectively engageable with oneof the large diameter portion and the small diameter portion so as tochange the rotating position of the horizontal shaft.
 11. The pickerdevice as set forth in claim 10,wherein said elastic means is a memberacting on the stop shaft.
 12. The picker device as set forth in claim1,wherein said down-picker mechanism is disposed in opposition to saidup-picker mechanism with the knitting cylinder disposed therebetween ina diametrical direction thereof.
 13. The picker device as set forth inclaim 1,wherein said down-picker mechanism and said up-picker mechanismare disposed with a phase difference of 90° along the circumference ofthe knitting cylinder.